These derivatives are readily obtained by alkylation of 2 - mercaptopyridine and alkyl halides under alkaline conditions.这些衍生物可以容易地在碱性条件下通过 2- 巯基吡啶和卤代烷的烷基化而得到.The different contents of various alkylation products were ob...
The Octane Number is retained owing to HZSM 5 � � s excellent ability of aromatization, isomerization and alkylation.HZSM-5沸石对汽油的降烯烃作用得益于其优异的芳构化 、 异构化和烷基化性能.These derivatives are readily obtained by alkylation of 2 - mer...
倒闭和失业的消息又在一次次地反复宣布着。Closures and job losses are again being announced with monotonous regularity.英国航天部门2万多人面临失业的危险。At stake are more than 20,000 jobs in Britain's aerospace sector.那些失业的人们想方设法以支付超市的账单。Those who have ...
脉络膜通过许多血管为视网膜供应血液.The choroid coat carries many blood vessels to supply the retina.晶状体是脉络膜石晶状体平面上向前扩大的部分.The ciliary body is an anterior dilation of the choroid at the level of the lens.它被脉络膜分开以至于不再起作用了.It is separated f...
The heavy rain driving against the windows made the room prematurely dark.暴雨敲打着窗户，房间早早就暗了下来。Weeks of heavy rain have washed away roads and bridges.几周的大雨将道路和桥梁都冲垮了。The heavy rain has caused floods in many parts of the cou...
a cadet in the armed forces军队里的军校学员Nicholas is a new cadet.尼古拉斯是海军学校的一名新学员.At that time every cadet had to be'smuggled " in.每个学员都得“潜越 ” 入境.He is a West Point cadet now.他现在是西点军校的学生了....the Cadet Corps.学员军训队IELTS Clas...